Free online calculators,
instant results.
Percentages, dates, loans, health, construction and AI costs. Every tool runs in your browser — nothing to install, nothing uploaded.
Math 05
Percentage Calculator
Percentages, discounts, increases and reverse percentages, solved instantly.
Fraction Calculator
Add, subtract, multiply and divide fractions with fully simplified results.
Random Number Generator
Random numbers by range or list, with or without repeats.
Dice Roller
Roll 1 to 6 dice (d4 to d20) with a rolling animation.
Circle Area Calculator
Area, circumference and diameter from any one measurement.
Dates & Time 02
Finance 08
Auto Loan Calculator
Monthly payment, total interest and the full amortization table.
Airbnb ROI Analyzer
Cash flow, cap rate and profitability scenarios for short-term rentals.
AI Token Cost Calculator
Estimate API budgets for GPT, Claude and Gemini from token usage.
Compound Interest Calculator
Project investment growth with compounding frequency and recurring contributions.
Mortgage Calculator
Monthly payment, total interest and amortization chart for a home loan.
CAGR Calculator
Compound annual growth rate between a starting and ending value.
IRR Calculator
Internal rate of return from an initial investment and a series of cash flows.
Loan Interest Rate Calculator
Find the interest rate from a loan amount, payment and term.